Adjustable chair back



Jan. .22, 1929.

E. o. KLEMM ADJUSTABLE CHAIR BACK 2 Sheets-Sheet 1 Filed Feb. 9, 1925Jan. 22, 1929. 1,699,894

E. O. KLEMM ADJUSTABLE CHAIR BACK Filed Feb. 9, 1926 2 Sheets-Sheet 2Patented Jan. 22, 1929.

ME STATES EDWIN O. KLEMM 0F SAGINAW, MICHIGAN.

ADJUSTABLE CHAIR BACK.

Application filed February The present invention relates to anadjustable back for chairs, and has for its object to provide a deviceof thischaracter which embodies novel features of construction, wherebythe chair back can be readily adjusted to diflt'erent positions andlocked at that particular inclination or position which may be desiredfor the comfort of the occupant of the chair.

Further objects of the invention are to provide a chair back adjustingdevice which can be readily applied to a chair without disfiguring thesame, which enables the inclination of the chair iack to be adjusted byproper manipulation of the chair back without touching any of the partsof the supporting device, and which enables the inclination or positionof the chair back to be quickly adjusted by the occupant of the chair,and at the same time prevents such a sudden drop of the chair back aswould be accompanied by a heavy shock and perhaps breakage of the parts.I

Certain embodiments of the invention are shown and described in thisapplication for illustrative purposes, although it will be understoodthat many modifications and changes can be made in the details ofconstruction without departing from the spirit ofthe invention.

For a full understanding of the invention reference is to be had to thefollowing clescription and accompanying drawings, in which, 7

Figure 1 a perspective view of atragmentary portion of a chair providedwith a swinging back having a supporting and ad justing mechanism whichis constructed in accordance with the invention, aportion of the chairback being broken away to disclose the mechanism at the back thereof.

Figure 2 is a rear view of the rack mechanism, showing the same asdetached from the chair. 1

Figure 3 is a longitudinal sectional view through the same.

Figure 4; is an enlarged transverse sectional view on the line HofFigure 3.

Figures 5 to 9 inclusive are fragmentary portions of a chair back whichis provided with a rack mechanism constructed in ac cordance with theinvention, showing the s1 ccessive positions which are assumed by theparts as the chair is manipulated to bring the cross rod into engagementwith a lower 9, 1926. SerialNo. 87,054.

notch and support the chair back at a slightly greater inclination.

Figures 10 to 13, inclusive are fragmentary views of portions of themain rack and retriever rack showing in a rather diagrammatic manner theaction of the rack bars when the cross rod is shifted from engage mentwith one of the notches of the main rack into engagement with the nextlower notch of the main rack.

Figure 14 is a side view of a portion of a chair back provided with aslightly modified construction of the rack mechanism, the normalposition of the retriever rack being shown by full lines, while thepositionthereof when swung rearwardly is indicated by dotted lines.

Figure 15 is a transverse sectional view on the line 15-45 of Figure14:.

Corresponding and like parts are referred to in the followingdescription andfindicated on all of the views of the drawings by likereference characters.

Referring to the drawings, the reference character A designates a chairback which, asshown by Figure 1, has a'pivotal connec tion B with theframe C of the chair, where+ by it can be tilted into difierent angularpositions. A mainrrack bar 1 is rigidly se cured to the rear of thechair back by suit-" able fastening members, such as those inclicated at2, and a selected notch of this rack bar 1s adapted to be engaged by across rod 3 to support the back in. an adjusted position.

The crossrod is connected at its ends to the swinging arms 41 which arepivotally connected to the frame G of the chair, so that the cross rodcan have the necessary up and down swinging movement to bring it intoengagement with any selected one of the notches of the main rack bar 1tosupport the chair back in the desired position.

The notches of the main rack bar 1 are formed with upwardly facingshoulders or seats i and inclined sides 1 and a keeper 5 is associatedwith the rack in a spaced and parallel relation thereto so that it willengage the cross rod 3 and serve to guide the cross rod up or down afterthe cross rod has been disengaged from the notches of the main rack 1and swung rearwardlytherefrom.

A retriever rack 6 is mounted back of the main rack 1, having a limitedmovement toward and away therefrom. As shown on the drawings, the endsof the retriever rack 6 are connected by swinging links 7 tocorresponding ends of the main rack, and the retriever rack is therebysuspended in such a manner that it normally tends to swing by gravityinto engagement with the main rack. In the construction shown by Figures1 to 4 of the drawings, the retriever rack 6 is arranged back 01" themain rack 1 and is formed with a longitudinal groove 6 which provides aclearance space-to re ceive the keeper 5 when the retriever rack is innormal position against the main rack. A

The teeth of. the retriever rack are formed with the upwardly facingshoulders 6? and inclined sides 6, and are so arranged that theshoulders 6 thereof will be at an elevation above the correspondingshoulders 1 of the main rack bar when the retriever rack is swungagainst the main rack.

The successive movements of the parts incident to shifting the cross rod3 from en gagement with one of the notches of the main rack 1 into enagement with the next lower notch thereo to support the chair back at aslightly greater inclination are illustrated in their proper sequence byFigures 5to 9 of the drawings. In Figure 5 thereof the cross rod 3 isshown as engaging the third notch fromthe bottom of the main rack 1. Inorder to change the adjustment of the chair back it is grasped by thehand and tilted forwardly a sufficient amount to permit the cross bar 3to swing by gravity away from the rack bar 1 and against the keeper 5.The cross bar at the same time engages the inclined portion of one ofthe teeth of the retriever rack 6 and swings the retriever rackrearwardly, the parts then assuming the position shown by Figure 6.Should it be desired to swing the chair back upwardly toward a verticalposition, the cross rod 3 will be directed upwardly by engagement withthe keeper 5 as the chair back is moved upwardly and when the desiredinclination has been reached the chair backcan be released, whereuponthe cross rod will be brought into engagement with one of the teeth ofthe main rack to support the chair back. a a a In the event it isdesired to lower the chair back, it is permitted to drop rearwardlyafter being first moved forwardly a suflicient amount to disengage thecross rod 3 from the main rack 1. Upon this subsequent rearward movementof the chair back the cross rod 1 slides downwardly along the keeper 5until it is engaged by the shoulder 6 of the next lower notch of theretriever rack as shown by Figure 7. This arrests the sliding movementof the cross rod along the keeper and upon further movement of the chairbackthe cross rod is moved toward the main rack by means of theretriever rack, as shown by Figure 8. The further downward movement ofthe chair back causes the cross rod to be moved from the notch of theretriever rack 6 into the notch of the main rack 1 which is just belowthe notch of the main rack with which the rod was previously inengagement. This movement of the chair back can be repeated to bring thecross rod into engagement with a still lower notch of the main rack ifit is desired to support the chair back at a greater inclination. Itwill thus be obvious that the chair back can be elevated as far as isdesired by a single upward movement, although it can only be lowered onenotch at a time, this beng desrable as a factor of safety to preventsudden and unintended drops whic might be caused by carelessness andresult in injury or damage to the chair.

The successive steps in a downward adjustment of the chair back are alsoillustrated by Figures 10 to 13, inclusive of the drawings. In Figure 10the cross rod 3 is in normal engagement with one of the teeth of themain rack bar 1 and the retriever rack 6 is in engagement with the mainrack bar. Figure 11 shows the position of the parts when the chair backis raised sufficiently to disengage the cross rod 3 from the main rackand permit the cross rod to move rearwardly into engagement with thekeeper 5 at the same time swinging the retriever rack 6 rearwardly.Figure 12 shows the position of the parts upon the initial rearwardmovement of the chair back, the cross rod 3 having been arrested in itsdownward movement along the keeper 5 by engagement with the next lowernotch of the re triever rack 6. The final position of the parts is shownby Figure 13, showing tllt' cross rod 3 as aving been brought intoengagement with the next lower notch of the main rack 1 by thesubsequent downward movement of the chair back. The retriever rack 6 issupported by the links 7 so that it always has a parallel relation tothe main rack as it swings downward and away from the same, and itnormally swings by gravity against the main rack, although it is notsufliciently heavy to offer material assistance to the downward movementof the cross rod 3 when the latter is disengaged from the main rack.

A slight modification is shown by Figures 14 and 15, in which the keeper5" is formed integral with the main rack 1", and the re triever rack ismounted. at one side of the keeper, being supported by the swinging arms4, and engaging stop )lIlS 8 to limit the inward movement thereo Thenotches of the main rack 1 and the retriever rack 6 are formed andarranged in the same relation to each other as previously described andengage the crossrod 3 in the same man ner. Both forms of the inventionprovide a construction which will effectively support the chair back atany desired angle and permit the chair back to be adjusted to adifferent angle without difiiculty, such adjustment being possible bymanipulation of the chair back without the necessity oi touching therack mechanism or cross rod.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is: a a

1. In a device of the character described, the combination with atiltably mounted back member, of means for adjustably supporting theback member, and means including a rack and a device having a pluralityof seats and actuated longitudinally of the rack by movements of theback member to vary the adjustment of the supporting means.

2. In a device of the character described, the combination with a fixedpart of a tilt ably mounted back member, means for adjustably supportingthe back member including a toothed member, a cross bar carried by thefixed part, and movable means disposed opposite the toothed member to beactuated by temporary engagement with said cross bar, said movable meanshaving means engaging said cross bar whereby the connecting device islimited in its travel to the distance between two successive teeth ofthe toothed member to prevent a downward adjustment of the supportingmember for more than a single tooth at each operation.

3. In a device of the character described, the combination with atiltably mounted back member, of means for adjustably supporting theback member, and means including a rack and an opposite carrier having aseries of seats staggered in relation to the rack and actuated bysuccessive back and forth movements of the back member to lower the samewith a step by step action.

l. In a device of the character described, the combination with atiltably mounted back member, and a transverse rod, of a rack mountedupon the back member and formed with a series of notches any selectedone of which is adapted to engage the rod, and means separate from saidrod and disposed to temporarily receive the red when actuated bymovements of the back member and limited in its travel to shift the rodfrom one notch into engagement with the next successive notch of therack.

5. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back member and formed with a series of notches anyselected one of which is adapted to engage the rod, and a retrievermember movable toward and away from the main rack and having a seatadapted to be temporarily engaged by the transverse rod and limited inits travel from a position opposite one notch to a position opposite thenext succeeding notch of the main rack to efiect a step step downwardadjustment.

6. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back member and formed with a series of notches anyselected one of which is adapted to receive the rod, a retriever memberextending longitudinally of said rack and having a plurality of seats,swinging links connecting the retriever member to the rack whereby theretriever member is movable toward and away from the rack and normallyswings toward the same by gravity, said retriever member being adaptedto temporarily receive the transverse rod and return it to a diilerentnotch of the main rack upon a back and forth movement of the backmember.

7. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back and formed with notches any selected one of whichis adapted to engage the rod, a keeper extendmg along the rack in aspaced relation thereto for guiding the rod along the rack, and aretriever member movable in parallelism to the rack and having aplurality of seats adapted to en age the rod and return it to adiflerent note 1 of the main rack upon a back and forth movement of theback member.

8. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back member and formed with a plurality of notches anyse lected one of which is adapted to engage the rod, a retriever member,and swinging links connecting the retriever member to the main rackwhereby it is movable toward and away from the main rack, said retrievermember being formed with notches which have a staggered relation to thenotches of the main rack, whereby it will engage the i rod and return itto a different notch of the main rack upon a back and forth movement orthe back member.

9. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back and formed with a plurality of notches anyselected one of which is adapted to engage to receive the rod and returnit to adifierent notch of the main rack upon a back and forth movementof the back member.

10. In a device of the character described, the combination with atiltably mounted back member and a transverse rod, of a main rackmounted upon the back member and formed with a plurality of notches anyselected one of which adapted to receive the rod, a keeper extendingalong the rack in a spaced relation thereto for guiding the rod alongthe rack, a retriever rack, swinging links connecting the ends of theretriever rack to the main rack whereby the retriever rack is movabletoward and away from the main rack and always has a parallel relationthereto, the notches of the main rack and retriever rack havin gupwardly facing seats and inclined aides and the seats of the retrieverrack being above the corresponding seats of the main rack, whereby upona back and forth movement of the back member the retriever rack willreceive the rod and return it to a di'l'lerent notch of the main rack.

In testimony whereof I aflix my signature.

EDWIN O. KLEMM.

